What is electronic component whose picture on the link below all about ?

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQnjJ0KcZ1ukesHcUFPcvePVz4yGarXsn1WiQ&usqp=CAU

 

common mode choke.
Generally used for interference suppression on devices connected to the mains supply, along with Class-X capacitors

 

Yes, it does look like a common mode choke, intended to present a higher impedance to noise. They can also function as a transformer, but that does not seem to be the intention.

 

Choke usually found in switch mode power supplies.